NBS Create and Level 2 BIM
by Dr Stephen Hamil
Director of Design and Innovation at NBS
The UK Government Construction Strategy was published by the Cabinet Office in May 2011. The report announced the Government's intention to require collaborative 3D building information modelling (BIM) on its projects by 2016. This requirement was defined as Level 2 BIM and the information management process to achieve this is defined in PAS 1192-2:2013. This PAS (Publicly Available Specification) builds on the existing Code of Practice for the collaborative process, defined within BS 1192:2007.
In this article, Stephen Hamil looks at how the innovative specification tool, NBS Create, can be used as a key collaboration tool within a level 2 BIM project. However, this article does not cover the strategy, brief or definition stage of the project. The RIBA Bookshops publication Assembling a collaborative project team is recommended in terms of getting a project off to the best possible start.
1. Collaboration and work in progress
Within a collaborative project team there is information that is considered work in progress to particular members of the team. There is also information that may be referenced by all members of the team from a common shared location.
When considering work in progress information within an organisation, NBS Create has a number of key features to support writing a specification.
1.1 Clarity of decision making
When working collaboratively, it is important to know who made a particular decision and when. Within NBS Create, this information is recorded and can easily be displayed in the editing window. Figure 1.1 below illustrates where members of the specification team (JRG and RT) have made decisions.
Figure 1.1 Clarity of decision making
1.2 Project notes
During the specification process, collaboration may be required to make the correct decision. Within NBS Create it is possible to add your own guidance notes against any of the specification clauses. This allows key decisions to be flagged so that the team can quickly return to them at a later date. In Figure 1.2 below the Notes Report is shown and each note is linked to a specific decision that is required.
Figure 1.2 Project notes
1.3 Clarity of information completeness
To take work in progress to a stage where particular members of the project team are willing to share it with all members, it is important to know what information is not complete. Within NBS Create the user may generate an 'Empty values report'. This lists the empty values in the specification so that an indication of decisions yet to be taken can be seen. Where information is to be issued from the work in progress area, the user may select a standard phrase of text for each empty value such as 'To be determined'. Figure 1.3A below shows the empty values report and Figure 1.3B shows published information using the phrase 'To be determined'.
Figure 1.3A – Empty values report
Figure 1.3B – Empty values publication
1.4 A view on what has changed
At any stage, the user may create a milestone across all of the information in the specification. This allows information to be compared between its current state and any previous milestone. Figure 1.4A shows a milestone being added into the specification model. Figure 1.4B shows the comparison of information between its previous state and this milestone.
Figure 1.4A – Inserting a milestone
Figure 1.4B – Comparing information between milestones
1.5 Say it once and in the right place
One of the basic principles of coordinating project information is to 'say it once and in the right place'. NBS Create is based on a well-structured relational database which facilitates this principle. In Figure 1.5 it can be seen that specification information shared by five different products (a collection of different sealants and fillers) is being written once. This means that if this information is changed in any of these clauses, it is updated against each of the others.
Figure 1.5 – Shared NBS clauses
1.6 Coordination of design and specification
Within the coordinated data environment of any work in progress, there will be graphical and non-graphical information. The specification clearly plays a big part in the non-graphical information; however, coordinating this with the graphical information is a challenge that has faced the construction industry throughout the ages.
NBS now has plug-ins for leading design BIM tools such as Autodesk Revit, Graphisoft ArchiCAD and Nemetschek Vectorworks. This allows information to be coordinated between the specification model and the design model. In Figure 1.6 it can be seen that the plug-in tool is indicating where information in both federated models is inconsistent. The design team can then correct this information within their work in progress area to ensure that whenever it is passed to the shared area it is fully coordinated.
It is estimated that the annual cost of poorly assembled data to the UK construction industry is up to £2bn. A blog post looking at a breakdown of this is at:http://constructioncode.blogspot.co.uk/2013/08/the-cost-of-poorly-assembled-data-to.html.
Figure 1.6 – Shared information between design and specification
2. Collaboration and shared information
When a member of the design team is happy that their information is of a quality that can be shared with all other members working on the design, it should be placed in an agreed shared area. Other design organisations may then use this as reference material for their own design development.
Information in the following formats should be shared:
- The native file formats (for example, the NBS Create, ArchiCAD or Revit file)
- Data from the native file formats to the COBie-UK-2012 schema
- PDF exports of the above information.
Further information on COBie-UK-2012 can be found athttp://www.bimtaskgroup.org/cobie-uk-2012/.
2.1 A common classification system
Where information is coming together from many design disciplines it is important that they all agree on the classification system that will be used. NBS Create has specification libraries for use by all major design disciplines that work on a building project – these meet the need of architects, structural engineers, mechanical engineers, electrical engineers and landscape architects. All of this content is classified by Uniclass 2 tables for systems and products. This allows for a coherent information set across the collaborative project team.
The NBS Create update functionality notifies users when library
content is modified. So, as Uniclass 2 develops further, project
teams will be notified of changes and will have the choice as to
when to upgrade.
Figure 2.1 below shows information from a number of different disciplines in a single coherent classification system across the project team.
Figure 2.1 Example specification output in shared area
2.2 Export to COBie
In the previous example, PDF is shown as a file format for data sharing. The advantage of PDF is that it is to an open standard and does not require a proprietary software package to read it.
However, to achieve level 2 BIM, more than PDF information is required. The COBie format is a well-structured dataset representing the project in terms of its floors, the spaces on the floors, the components with the spaces and the specification of the types of components.
Although this data format is simple, collaboration between the many members of the design team across many models is not a simple task.
Within NBS Create, data in a format that can be easily imported into the single COBie dataset can easily be exported. In Figure 2.2 below, various types of products exported from NBS and their attributes are shown in this single COBie dataset.
Figure 2.2 – Example COBie dataset
2.3 A view on what has changed
If using the native NBS file format, the milestone functionality may be used to check any modifications. However, for recipients of information from NBS Create in PDF format, revision information can be added to the front of the exports. This allows all project team members to see what has changed in the information issued by a particular member. As this is created by the software and not manually generated, this is an efficient and accurate way of indicating what has changed.
Figure 2.3 shows an example revision cover sheet to a specification PDF exported from NBS Create.
Figure 2.3 Revision information clearly shown on all specification output in shared area
3. Collaboration and Level 3 BIM
The UK Government require their whole supply chain to work at collaborative level 2 BIM by 2016. This is not too far away and most organisations will have a strategy for how they will achieve this level of collaborative working. There will be some organisations that are already working at level 2 and are looking to what is next? The next step in competence, level 3 BIM, is currently being defined. There is an indication as to what it will contain at a high level in the BIM maturity documentation in PAS 1192-2:2013; this is considered briefly below.
iBIM is an integrated, single model view of all of the project information. This information will be online and transparent; it will have self–checking and artificial intelligence functionality. Mechanisms will be in place to ensure that the processes documented around level 2 BIM are not replaced with a 'free for all'.
The Industry Foundation Classes (IFC) data model developed by buildingSMART is an open, neutral and standardised specification BIM. The intention is that level 3 BIM will use IFC and not COBie for its open format data. Further information on IFC may be found at the website below: http://www.buildingsmart.org/standards/ifc.
At NBS we are members of buildingSMART UK, with representation on the UK Council of Management and also the Technical Steering Group. We have embraced IFC as a way of working. All of our National BIM Library objects respect the IFC schema and have file versions in IFC base format. We also have IFC beta export functionality linking information in the specification model with that in the design model.
3.3 IFD and IDM
The International Framework for Dictionaries (IFD) is now known as the buildingSMART Data Dictionary (bSDD). This is a mechanism that adds further meaning to an IFC model through defined attributes. This will also allow information to translate between different languages. Further information on IFD may be found at the website below: http://www.buildingsmart.org/standards/ifd.
The Information Delivery Manual (IDM) is now known as the buildingSMART standard for processes. This is a mechanism that specifies what information is required by a particular user at a certain point in time. http://www.buildingsmart.org/standards/idm.
At NBS, through our membership of buildingSMART UK, we are working with international partners to investigate IFD through trials with construction manufacturer data. NBS are also founder members of the BIM Technology Alliance, the technology team supporting the UK Government's Construction Strategy BIM Working Group. Our work for the BIM Task Group Labs area on information requirements through the digital plan of work followed the IFD and IDM principles. The results of this work can be found at http://www.bimtaskgroup.org/task-group-labs-portal/.
NBS Create is a tool that can be used within a collaborative level 2 BIM project. Within an organisation it helps improve clarity of decision making, has QA functionality, is based on a relational database and allows for coordination of the information and the graphics on a project. When this information is passed from 'work-in-progress' to 'shared', improved clarity across the collaborative project team is facilitated in NBS Create by the common classification system, export to COBie and revision functionality.
In terms of the journey to the next level of digital collaboration (level 3 BIM), NBS are one of those organisations helping to define the 'level 3 vision' through our work with national and international partners.
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